An innovative steel-timber composite floor for use in multi-storey residential buildings is presented. The research demonstrates the potential of these steel-timber composite systems in terms of bearing capacity, stiffness and method of construction. Such engineered solutions should prove to be sustainable since they combine recyclable materials in the most effective way. The floors consist of prefabricated ultralight modular components, with a Cross-Laminated Timber (CLT) slab, joined together and to the main structural system using only bolts and screws. Two novel floor solutions are presented, along with the results of experimental tests on the flexural behaviour of their modular components. Bending tests have been performed considering two different methods of loading and constraints. Each prefabricated modular component uses a special arrangement of steel-timber connections to join a CLT panel to two customized cold-formed steel beams. Specifically, the first proposed composite system is assembled using mechanical connectors whereas the second involves the use of epoxy-based resin. In the paper, a FEM model is provided in order to extend this study to other steel-timber composite floor solutions. In addition, the paper contains the design model to be used in dimensioning the developed systems according to the state of the art of composite structures.
Different methods, including bending tests and small and medium size shear tests, were used to assess the skin to stringer glue line shear strength of Radiata Pine Cross-Laminated Timber Derived Stressed-Skin Panels (CLT SSP). Bending test shear strengths were estimated using the mechanically jointed beam theory (gamma method) for CrossLaminated Timber (CLT) panels with modifications in the layers’ effective widths, and then compared with results from the small and medium size shear tests. Small and medium size shear tests proved to be possible methods for assessing bonding strength for factory production control. The small shear tests provided lower strength values and higher scatter results than those gathered from the medium size tests. The mean shear strength results obtained from bending tests were inferior to the values obtained from the small and medium size specimens. The bending tests proved necessary for assessing the mechanical behaviour of CLT SSP.
This book contains experiences and results of computer simulations in the field of research on glued laminated timber. Literature and references to the corresponding methodical approach are given to facilitate the access to the elementary basics. It also contains constructive explanations and critical annotations on modelling glued laminated timber for bending, tension and compression tests. Finally, the relevance of the simulation results for practical issues is discussed.
Timber-Concrete Composite (TCC) systems are comprised of a timber element connected to a concrete slab through a mechanical shear connection. When TCC are used as flexural elements, the concrete and timber are located in compression and tension zones, respectively. A large number of precedents for T-beam configurations exist; however, the growing availability of flat plate engineered wood products (EWPs) in North America in combination with a concrete topping has offered designers and engineers greater versatility in terms of architectural expression and structural and building physics performance. The focus of this investigation was to experimentally determine the properties for a range of proprietary, open source, and novel TCC systems in several Canadian EWPs. Strength and stiffness properties were determined for 45 different TCC configurations based on over 300 small-scale shear tests. Nine connector configurations were selected for implementation in full-scale bending and vibration tests. Eighteen floor panels were tested for elastic stiffness under a quasi-static loading protocol and measurements of the dynamic properties were obtained prior to loading to failure. The tests confirmed that both hand calculations according to the -method and more detailed FEM models can predict the basic stiffness and dynamic properties of TCC floors within a reasonable degree of accuracy; floor capacities were more difficult to predict, however, failure did usually not occur until loading reached 10 times serviceability requirements. The research demonstrated that all selected connector configurations produced efficient timber-concrete-composite systems.